With the development of the computer information technology and the display technology, 3D display technology has become a research focus in the display field. When human eyes are looking at a normal object, for the same scene, the left eye and right eye of the viewer receive images respectively. Due to the position variation of the pupil distance between two eyes of the viewer, two images with a slight variation appear on the retinas of the left eye and right eye of the viewer, which is called “binocular parallax”. The two images with the slight variation construct a “stereo image pair”. This principle is used by 3D (three-dimension) technology. For the same scene, a left eye image and a right eye image are made by photography. Upon displaying, the left eye image is only sent to the left eye of the viewer and the right eye image is only sent to the right eye of the viewer so that the “stereo image pair” is formed. After the “stereo image pair” is combined by the brain visual cortex, the stereo effect is formed, as illustrated in FIG. 1.
During the photography of the stereo image pairs, the left eye image and the right eye imaged are taken by two video cameras at different angles, and displayed on a screen by a playing device. Therefore, an overlapping image of the left eye image and the right eye image appears on the screen. When the viewer is watching the 3D image, by means of the filtering of polarized glasses or shutter glasses, the left eye image is sent to the left eye of the viewer and the right eye image is sent to the right eye of the viewer, which are combined by the brain visual cortex so that the stereo image is formed.
Ideally, the left eye of the viewer can only see the left eye image and the right eye of the viewer can only see the right eye image through stereo glasses. However, in reality, in either a beam division method of the polarized glasses or a time division method of the shutter glasses, an interference of the left eye image to the right eye image and an interference of the right eye image to the left eye occur, which is called a cross interference between the left eye image and right eye image displaying in the 3D display. The cross interference is an important factor determining the image quality of a stereo display system (including display device and stereo glasses). A severe cross interference will make it difficult to form the stereo image and cause a distortion so that the viewer has various degrees of asthenopia. Therefore, during the fabricating of the stereo display system, it is important to analyze and test the cross interference of the stereo display system. Delayed responses caused by various factors such as a image signal, a backlight, a display panel, stereo glasses will introduce the cross interference between the left and right eye image.